Why does it matter if anyone else listens to you?
Go to your college health center and ask for an evaluation. If they cannot do it, they surely can send you to the appropriate people who can.

You are an adult now. It's time to begin to take care of yourself. That's what being in college is all about. It's a transitional time. If mom won't help you, you need to help yourself. It's what growing up is all about.

And, as an aside,
For those of us with ADD/ADHD, a planner is almost an essential part of our lives, like air. You ought to get used to using it. It will make your life easier in the long run. Because a diagnoses of ADD/ADHD is not an excuse to fail. It only means that we have to find solutions to the challenges we face.
You can do it.

Peace!